Combination calipers and poising-tool.



E. BENSON.

COMBINATION OALIPEES AND'BOISING TOOL.

APPLICATION FILED 001. 30, 1908.

ANDREW uv GRAHAM cu. FHOTn-LIYNOGRAVNERS. WASHINGTON, n.0,

UlHllll IHHM Patentad May 31, 1910.

ELOF BENSON, OF YOUNGSTOWN, OHIO.

COMBINATION OALIPERS AND POISING-TOOL.

To all whom it may concern:

Be it known that I, ELOF BENSON, citizen of the United States, residingat Youngstown, in the county of Mahoning and State of Ohio, haveinvented certain new and useful Improvements in Combination Calipers andPoising-Tools, of which the following is a specification.

The object of my invention is to provide an efficient, simple andinexpensive caliper particularly adapted for use of watchmakers anddesigned as a truing and poising tool whereby the truing or poising of abalance wheel, or other wheels of a watch or clock, may be accuratelyaccomplished.

In the use of ordinary watchmakers calipers great care must be exercisedby the operator when adjusting the delicately constructed pivots of awheel to the bearings carried by the caliper jaws, and if not properlymanipulated, the pivots may be irreparably injured. With the eliminationof this defect in view the present invention contemplates theconstruction and arrangement of caliper arms or jaws pivotedintermediate of their ends and provided with jewel bearings adapted tooffer the least possible resistance to the wheel pivots when adjusted tothe jaws. A truing bar adjustably secured to the caliper arms isdesigned to register the slightest deviation or defect in the wheel asregards trueness and means for giving vibration to the jaws, whereby anyimperfection in the poise of the wheel may be determined.

For a full understanding of the invention and the merits thereof andalso to acquire a knowledge of the details of construction and the meansfor effecting the result, reference is to be had to the followingdescription and accompanying drawings, in which Figure 1 is a frontelevation of my improved caliper; Fig. 2 is an edge elevation thereof;and, Fig. 3 is an edge elevation partly in section, illustrating thepivotal point of the several parts.

Corresponding and like parts are referred to in the followingdescription and indicated in all the views of the drawings by the samereference characters.

Referring to the drawings, the numerals 1 and 1 designate two like armsprovided at corresponding extremities with jaws 2 and 2 comprisingoppositely curved portions, and at their opposite extremities with jaws3 and 3 of substantially straight formation.

Specification of Letters Patent.

Application filed October 30, 1908.

Patented May 31, 1910.

Serial No. 460,259.

These arms are preferably constructed of metal and pivoted to each otherintermediate their ends by a pivot pin t extending through registeringopenings in the oppositely formed transversely reduced portions 5 and 5and when assembled, the reduced portions which are circular, overlap(Fig. 3,) and permit relative movement of the arms to open or close thejaws as desired. The pin 4 is provided with a head l at one extremityand is formed with a threaded longitudinal opening at its oppositeextremity designed for the reception of an auxiliary screw 6.

Located on both sides of the arms at their pivotal point are plates 7and 7 provided with openings registering with the pivot openings in saidreduced portions 5 and 5 for the passage of the pin 4;, and an annularshoulder 4 formed upon said pin and resting upon the outer face of theplate 7 is designed to cooperate with the screw (3 to hold said platesand the reduced portion of the arms in their proper relative position.

The numeral 8 designates a spring interposed between the jaws 3 and 3and secured thereto as indicated at 9 and arranged to spread said jawsapart and the jaws 2 and 2 together. A stop screw 10 carried by the arm1 and operating in a threaded transverse opening in said arm is designedto counteract the tension of the spring 8 upon the jaws 3 and 3 and tohold the aws at the proper distance while the spring holds the jaws 2and 2 as close together as the screw will admit. The head 10 forms athumb piece by which the screw is manipulated, and is permitted to movetransversely of the arm l in the opening 11 formed in said arm, and theopposite end of said screw operates against the inner face of the shankportion of the arm 1 as indicated at 12.

Secured to the extremities of the jaws 2 and 2 and 3 and 3 are jewelbearings 13 and 14 respectively designed to receive the wheel pivots(not shown) and offer the least possible resistance to the movement ofthe wheel when suspended between the arms. The jaws 3 and 3, and jewelbearings let are particularly adapted for use in connection with theheavier and larger wheels of a watch or clock while the aws 2 and 2*with jewel bearings 13 are especially designed for the examination ofthe more delicately constructed wheels of a watch as for instance, abalance wheel.

The numeral 15 designates a truing or indicator bar provided at oneextremity with guide points 16 of the same general formation as thecaliper jaws 2 and 2 and a slotted shank portion 17 integrally a part ofsaid guide points and through which the pin 4 extends, is adjustablysecured to the caliper at one side by a hemispherical spring 18surrounding the pin 4L and interposed be tween the slotted shank portion17 and the head rof said pin. Said truing bar at the intersection of theguide points 16 and shank 17 is deflected toward the caliper jaws asindicated at 15 Fig. 2, to bring said guide points in the same planewith the upper face of the caliper arms without interfering with itsradial movement upon the pin 4. Vith such an arrangement the bar isadapted to slide with respect to the caliper jaws, and is also capableof angular or rotative movement whereby the bar may be used at eitherjaw end of the caliper and retained in any desired relative position bythe spring 18.

A threaded pin 19 is secured to the inner face of the caliper jaw 2 andprojects inward in the same plane with the aw, and is therefore beneaththe indicator bar, this pin being designed as a vibrator by which thedefective poise of wheels suspended between the caliper jaws isascertained. To this end, the pin is roughened, the roughening beingbest secured by forming screw threads on the pin. Such vibratorymovement at the jaw centers is set up by a pin or pointed instrument(not shown) drawn by the operator across the threaded pin 19 withsuiiicient violence to cause a series of very rapid vibrations in theinstrument, thus causing a suspended wheel to turn if not perfectlypoised and by such movement the defect is quickly and easily located.Feet or rests 20 located upon the jaws 2 and 2 intermediate of thepivotal point of the arms and the pin 19, and secured to said jaws,serve to elevate one end of the caliper from the work bench during anenforced suspension of the examination of a wheel, and are particularlydesigned to hold the caliper in a position upon a bench best adapted tosecure the proper vibration of the free ends of the caliper jaws whenpoising a wheel. The formation of the jaws 3 and 3 which aresubstantially straight enables the operator to readily hold andmanipulate the caliper said arms constituting a handle by which thecaliper may be held during the exami nation of a wheel to determine itstrueness.

lVith the arrangement of the several parts as shown the operation is afollows: For example when it is desired to test a balance wheel of awatch, the screw 10 is adjusted so that the jewel bearings 14: willreceive and firmly hold the wheel pivots and offer the least possibleresistance when the wheel is I I i I J revolved. The tension of thespring 8 is counteracted by the screw 10 and the delicately constructedwheel pivots are relieved of continued and varying degrees of pressureoccasioned by the manipulation of the caliper in the hands of theoperator. The balance wheel having been placed in position, the guidepoints of the indicator bar are moved close to the rim of the wheel andthe wheel when revolved may be examined from either side of the caliperand the trueness of the wh el determined. The wheel is next caused torevolve and any lateral deviation in its circumference, or in itsangular relation to the axis determined. These defects having beencorrected the wheel is again placed in position in the caliper bearingsfor the purposeof determining the correctness of its poise or balance.In the last mentioned portion of the operation, the caliper ispreferably placed upon a work bench or other convenient point ofobservation and rests upon the feet or rests in an elevated positionwithout interference by other objects. As before stated, the jewelbearings of the jaws offer the least possible resistance to the wheelpivots so that an instrument of any character drawn across the threadedor roughened pin 19 will cause or set up sufficient vibratory motion atthe jaw end to create or transmit an impulse to the wheel causing theheavy side to move downward by its own gravity.

As will be understood, a wheel, after adjustment to the jaws 2 and 2*,may be removed and replaced any number of times without disarrangeinentof the caliper parts, the jaws 3 and 3 acting as a handle which may bemanipulated to open the jaws 2 and 2 said jaws being returned by thetension of the spring 8 to their adjusted positions.

The jaws 3 and 3 are preferably used in the examination of the heavierwheels of a watch or clock, the indicator bar being turned upon the pin10 to an operative position at that end of the caliper, and theoperation in other respects is the same as before described.

Having thus described the invention what is claimed is: V

1. A tool of the character described, comprising a pair of arms formedat their extremities with aw members, a pivot pin securing the arms toeach other intermediate the extremities of the arms, bearings secured tosaid jaws, an indicator bar longitudinally shiftable on the pivot pin,and means for adjusting and controlling the positions of the arms andaws relatively to each other.

2. A tool of the character described, comprising a pair of arms formedat their extremities with jaw members, a pivot pin pivotally securingthe arms to each other, an indicator bar provided with a guide point andhaving a longitudinal slot through which the pivot pin passes, and meansfor adjusting the arms and jaws relatively to each other.

3. A tool of the character described, comprising a pair of arms formedat their extremities with jaw members and pivotally secured to eachother, and an indicator bar provided with opposed separated guidepoints, said bar being mounted on but longitudinally shiftable andadjustable with relation to said arms.

4. In a tool of the character described, a pair of arms formed at theirextremities with jaw members and pivotally secured to each other, one ofsaid arms being provided with a resilient pin distanced from said jawmember and projecting from the arm, said pin having a free end and beingroughened on its face whereby minute vibrations may be communicated tothe arms.

5. A tool of the character described, including a pair of arms formed attheir extremities with jaw members and pivotally secured to each other,means for holding the arms adjusted nearer to or farther from eachother, and a pin projecting inward from one of the said jaws and havinga free end, said pin having a roughened face, whereby minute vibrationsmay be communicated to the arms.

6. A tool of the character described, comprising a pair of arms formedat their extremities with jaw members and pivotally secured to eachother intermediate of the jaw extremities, a pivot pin connecting saidjaw members, an indicator bar provided with guide points andlongitudinally shiftable upon and rotatable about said pivot pin, meansfor holding the arms and indicator bar in their adjusted positions, anda pin projecting from one of said arms and extending inwardly toward theother of said arms and beneath the indicator bar, said pin being free atone end and having a roughened surface whereby minute vibrations may becommunicated to the arms.

7. A tool of the character described, comprising a pair of arms, eacharm formed at its opposite extremities with inwardly turned jaw members,each jaw member being provided with a caliper center, said arms beingpivoted to each other intermediate of their length, said arms on oneside of the pivot being longitudinally extended to form a handle wherebythe jaws at the opposite ends of the arms may be operated, a U- shapedspring arranged between the longitudinally extended arms and acting toclose the jaws at the opposite ends of the arms, said arms contactingwith each other at their middle portions, and one of said arms beingrecessed transversely, and a screwthreaded stop extending transverselythrough a screwthreaded passage in one of said arms, said stopprojecting at one end beyond the inner edge of the arm and adapted toengage with the edge of the opposed arm, the other end of the stop beingpro vided with a head whereby the stop may be rotated.

8. A tool of the character described, including a pair of arms formed attheir 0pposite extremities with jaw members, a pivot pin pivotallysecuring the arms together, adjustable heads on the pivot pin, anindicator bar having a slot through which said pivot pin passes, saidindicator bar being supported on one side of said heads, and an annularspring surrounding the pivot pin and engaging at its margin with theindicator bar.

9. A tool of the character described, comprising a pair of arms formedat their extremities with opposed jaw members, a pivot pin securing thearms to each other intermediate their extremities, bearings secured insaid jaws, and an indicator bar longitudinally shift-able on the pivotpin, said indicator bar being bifurcated at its extremity.

10. A tool of the character described, comprising a pair of arms, eachof said arms being reversely curved at opposite ends, a pivot pinconnecting the arms intermediate of their opposite ends, the arms thusforming two opposed pairs of jaws, one pair of aws forming the handlefor the opposite pair of jaws, an indicator bar longitudinally shiftableon the pivot pin, and means for adjusting and controlling the positionsof the arms and aws relatively to each other.

In testimony whereof I aflix my signature in presence of two witnesses.

ELOF BENSON. l/Vitnesses E. H. OTTING, J. H. HARVEY.

